Method for producing an avocado unsaponifiable rich in furan lipids

ABSTRACT

The present invention relates to a process for obtaining a furan lipid-rich unsaponifiable material from avocado, which comprises the successive steps ( 1 ) of controlled dehydration of fresh avocados or of avocados that have undergone preliminary transformations, ( 2 ) of extraction of the oil from dehydrated fruit, ( 3 ) of a heat treatment of the extracted oil and of a step of concentration of the unsaponifiable fraction of the oil or alternately, these two operations possibly being carried out successively in this order or in the reverse order, and finally ( 4 ) a step of saponification and of extraction of the unsaponifiable material.

The present invention relates to a process for obtaining a furanlipid-rich unsaponifiable material from avocado.

Avocado comprises, in a known manner, particular lipids of furan type,the main component of which is a linoleic furan:

Thus, according to the invention, the expression “furan lipids fromavocado” means components corresponding to the formula:

in which R is a C₁₁-C₁₉ and preferably C₁₃-C₁₇ linear hydrocarbon chainthat is saturated or comprising one or more ethylenic or acetylenicunsaturations. These furan lipids from avocado have been describedespecially in Farines, M. et al, 1995, J. of Am. Oil Chem. Soc. 72, 473.

The unsaponifiable material is the fraction of a fatty substance which,after prolonged action of an alkaline base, remains insoluble in waterand may be extracted with an organic solvent. Five major groups ofsubstances are present in most of the unsaponifiable materials of plantoils: saturated or unsaturated hydrocarbons, aliphatic or terpenicalcohols, sterols, tocopherols, carotenoid pigments and xanthophylls.

Patent FR 91 08301 describes a process for obtaining an unsaponifiablematerial from avocado starting with an avocado oil enriched in one ofits fractions, known as fraction H, which in fact corresponds to thesesame furan lipids. The preparation of such an unsaponifiable materialthat is rich in furan lipids, the content of which can range from 30 to60%, is essentially conditioned by a controlled heating of the freshfruit, sliced beforehand into thin slices, at a temperature of between80 and 120° C., and for a duration preferably chosen between 24 and 48hours. In this process, the heat treatment may be preceded bydehydration of the fruit, but, preferably, it is performed concomitantlywith drying of the fruit. This heat treatment allows, after extraction,the production of a furan lipid-rich avocado oil. Finally, using thisoil, the unsaponifiable fraction is obtained according to a standardsaponification process, completed by step of liquid-liquid extraction.

A first drawback of this process is the need to heat to a relativelyhigh temperature, at least equal to 80° C., for relatively long periods,1 to 2 days, slices of fruit rich in lipids that are readily oxidizableunder these conditions. In addition, this type of heat treatment bringsabout, in plant-based food matter, secondary degradation reactions thatare well known to those skilled in the art, such as the Maillardreactions, which cause unwanted browning of the products, and theappearance of flavours and aromas that are often unpleasant.

Moreover, this type of heat treatment, carried out in air, withoutpreliminary establishment of an inert atmosphere, may be accompanied bymajor chemical changes, especially in the presence of heat-sensitivesubstrates such as lipids (e.g. unsaturated fatty acids) and theirunsaponifiable fraction (e.g. vitamin E). Thus, the heat processes willfavour the heat-oxidation of the substrates, free-radical reactionsresponsible for the appearance of peroxides, and also intramolecular orintermolecular condensation reactions that are the cause of theformation of heavy products.

In fact, the conjunction of these uncontrolled secondary processes maylead to a major impairment of the organoleptic properties of the treatedproducts and to a profound change in their physicochemical properties.Finally, this type of product may be the cause of a drastic reduction inthe yield of target product, in this instance furan lipids, and may thusbe harmful to the overall economic viability of the process.

Given the therapeutic value of the furan lipid-rich unsaponifiablematerial from avocado for its beneficial and curative action onconnective tissue, especially in inflammatory pathologies such asosteoarthritis, periodontitis and scleroderma, and its generally highcost, there is thus strong interest in preparing, in the best possibleyield, unsaponifiable fractions from avocado oil that are rich in furanlipids and very poor in oxidation and condensation compounds.

The Applicant has thus developed a process for obtaining in high yieldan unsaponifiable material from avocado that is rich in furan lipids,i.e. with a content ranging from 50% to 80%, and that has low contentsof heavy products and peroxides.

This process comprises the following successive steps:

-   -   (1) a step of controlled dehydration of fresh avocados or of        avocados that have undergone preliminary transformations,        performed at a temperature of between −50° C. and 75° C.,    -   (2) a step of extraction of the oil from the dehydrated fruit,    -   (3) a step, alternatively,        -   a. of heat treatment of the extracted oil at a temperature            that can range from 80 to 150° C., optionally under an inert            atmosphere, and then a step of concentration of the            unsaponifiable fraction of the oil, or        -   b. of a step of concentration of the unsaponifiable fraction            of the oil, followed by a heat treatment at a temperature            that can range from 80 to 150° C., optionally under an inert            atmosphere, followed by    -   (4) a step of saponification and extraction of the        unsaponifiable material.

The expression “avocado that has undergone preliminary transformations”means the co-products derived from the processes of extraction of thefresh avocado oils, especially those derived from the “centrifugation”processes. Thus, in terms of “avocado that has undergone preliminarytransformations”, mention may be made especially of i) avocado milks 5(semi-liquid puree) obtained by pressing the pulp, or ii) the productsof clearing of the partially de-oiled pulp by centrifugation,by-products generally present at the outlet of the centrifuge sieves, orthe centrifugation pellets produced during the separation. Other sourcesof avocado that come under the expression “avocado that has undergonepreliminary transformations” may also be mentioned. Thus, avocado cakes,co-produced during the cold-pressing of the fruit (fresh or dried) orliquid-solid extraction of avocado oil from fresh or dried fruit, usingan organic solvent, may also constitute, in this form, an alternativestarting material that may be used in the context of the presentinvention. Finally, although poor in oil, avocado kernels maypotentially constitute a source of lipids and may be used in the contextof the present invention.

The term “dehydration”, performed in step (1) of the process, moregenerally means all of the techniques known to those skilled in the artwhich allow the water to be removed from a compound. Among thesetechniques that may be mentioned are drying under a stream of hot air orunder a controlled atmosphere (e.g. nitrogen), at atmospheric pressureor under vacuum, in a thick layer or a thin layer, and also microwavedrying, spray-drying, freeze-drying and osmotic dehydration in solution(direct osmosis) or in solid phase (e.g. drying in osmosis bags). In thecontext of the present process, for reasons of ease of industrialimplementation and for reasons of cost, drying in ventilated dryers, ina thin layer and under a stream of hot air, at a temperature of between70 and 75° C. for 8 to 36 hours, is preferred.

The extraction step (2) may be carried out by any means known to thoseskilled in the art, preferably by a simple cold-pressing or by means ofa solvent at low temperature.

According to the process of the invention, the heat treatment stepcarried out in step (3) a. or b. may be performed in the presence orabsence of an acid catalyst. The term “acid catalysts” means, in thebroad sense, homogeneous mineral and organic catalysts, such ashydrochloric acid, sulphuric acid, acetic acid or para-toluenesulphonicacid, but also, and preferably, heterogeneous solid catalysts such assilica, alumina, silica-aluminas, zirconias, zeolites and acidic resins.Acidic aluminas with large specific surface areas, i.e. at least equalto 200 m²/g, will be chosen in particular. Catalysts of acidic aluminatype are preferred for carrying out the process of the invention.Advantageously, this heat treatment is carried out under a continuousstream of nitrogen. Preferably, the heat treatment temperature isbetween 80 and 130° C.

The concentration step in step (3)a. or (3)b. may be a coldcrystallization or a molecular distillation.

The molecular distillation may be performed at a temperature of between180 and 260° C. while maintaining a pressure of between 10-3 and 10-2mmHg. This step of molecular distillation of the unsaponifiable materialis preferably performed using a device chosen from moleculardistillation devices of centrifugal type and molecular devices ofwiped-film type. Molecular distillation devices of centrifugal type areknown to those skilled in the art. For example, patent application EP493 144 describes a molecular distillation device of this type. Ingeneral, the product to be distilled is spread in a thin layer over theheated surface (hot surface) of a conical rotor rotating at high speed.The distillation chamber is placed under vacuum. Under these conditions,evaporation takes place rather than boiling, from the hot surface, ofthe constituents of the unsaponifiable material, the advantage beingthat the oil and the unsaponifiable material (these products beingnotoriously fragile) are not degraded during the evaporation. Moleculardistillation devices of wiped-film type, which are also known to thoseskilled in the art, comprise a distillation chamber equipped with arotating doctor blade, allowing the product to be distilled to be spreadcontinuously over the evaporation surface (hot surface). The productvapours are condensed by means of a cold finger placed in the centre ofthe distillation chamber. The peripheral feed and vacuum systems arevery similar to those of a centrifugal distillation device (feed pumps,vane vacuum pumps and oil diffusion pumps, etc.). The residues anddistillates are recovered in glass flasks by gravitational flow.

Step (4) of saponification of the oil or of the oily extract may becarried out in the presence of potassium hydroxide or sodium hydroxidein alcoholic medium, preferably ethanolic medium, followed by one ormore extraction(s). Extraction with a suitable organic solvent(liquid-liquid extraction) in-order to separate the fatty acid soaps andthe unsaponifiable compounds, is particularly suitable for use. Theappropriate organic solvent may be chosen, for example, from the groupof alkanes, haloalkanes, aromatic solvents, ethers such as methyltert-butyl ether (MTBE) and ethyl ether, or any other suitable solventthat is immiscible with the aqueous-alcoholic solution. A haloalkanewill preferably be chosen, in particular 1,-2-dichloroethane.

The extraction solution obtained is then preferably centrifuged,filtered and then washed with water to remove the residual traces ofalkalinity. Finally, the extraction solvent is evaporated thoroughly torecover the unsaponifiable material. Needless to say, it is alsopossible to include additional operations known to those skilled in theart, such as a deodorization step.

The following non-limiting examples illustrate the invention.

Starting with the same batch of fresh avocados, with a net weight of1000 kg, of the Fuerte variety from South Africa, 6 sub-batches of 50 kgeach are made.

EXAMPLE 1 Process of Vigorous Heat Treatment of the Fruit

50 kg of fresh avocados are cut into thin slices 2 to 5 mm thick,including the kernel, using a disc slicer. The drying device is atemperature-regulated oven with a stream of hot air. The sliced avocadosare spread to a thickness of 4 to 5 cm on staged trays. The dryingtemperature is set at 85° C. and its duration is 48 hours. Once dried,the fruit is ground and then subjected to a cold pressing. Thisoperation is performed on a small laboratory Komet press. The extractedoil is then filtered through a Büchner funnel, and then stored undernitrogen protected from light and moisture.

The oil obtained is then distilled in a Leybold KDL 4 wiped-filmmolecular distillation device, at a temperature of 230° C. and under avacuum of 10⁻³ mmHg. The yield of distillate for this operation is 9.2%.

The distillate obtained is saponified for 4 hours at reflux, in thepresence of 175 g of 50% potassium hydroxide and 875 g of ethanol, in aglass reactor equipped with a mechanical stirrer and on which is mounteda condenser. At the end of the reaction, the mixture is cooled to 30° C.and then diluted by adding demineralized water. The aqueous-alcoholicsolution (AAS) obtained is then extracted with 1,2-dichloroethane usinga separating funnel.

The organic phases are then combined and dried over anhydrous sodiumsulphate. The dissolved unsaponifiable fraction is finally recoveredafter evaporating off the solvent and drying under vacuum. This step iscarried out in a rotary evaporator, at 70° C., under a vacuum of 1 mmHgfor 2 hours. 126 g of unsaponifiable fraction from avocado are thusrecovered, and are then stored under nitrogen while awaiting analysis.

The physicochemical and chromatographic analysis of this fraction gavethe following results:

-   -   peroxide value: 87.2 meq O₂/kg    -   saponification number: 12.3 mg KOH/g    -   incineration residue: 0.3%    -   furan lipid content: 49.2%    -   fatty alcohol content: 14.7    -   heavy compounds: 22.3%

EXAMPLE 2 Process for the Vigorous Heat Treatment of the Oil

50 kg of fresh avocados are cut into thin slices 2 to 5 mm thick,including the kernel, using a disc slicer. The drying device is atemperature-regulated oven with a stream of hot air. The sliced avocadosare spread to a thickness of 4 to 5 cm onto staged trays. The dryingtemperature is set at 70° C. and its duration is 48 hours. Once dried,the fruit is ground and then subjected to a cold pressing. Thisoperation is performed on a small laboratory Komet press. The extractedoil is then filtered through a Büchner funnel, and then stored undernitrogen protected from light and moisture.

This oil is then heated at 85° C. for 48 hours, under a continuousstream of nitrogen, in a glass reactor equipped with a mechanicalstirrer.

The oil obtained is then distilled in a Leybold KDL 4 wiped-filmmolecular distillation device, at a temperature of 230° C. and under avacuum of 10⁻³ mmHg. The yield of distillate for this operation is 9.4%.

350 g of this distillate are saponified for 4 hours at reflux, in thepresence of 175 g of 50% potassium hydroxide and 875 g of ethanol, in aglass reactor equipped with a mechanical stirrer and on which is mounteda condenser. At the end of the reaction, the mixture is cooled to 30° C.and then diluted by adding demineralized water. The aqueous-alcoholicsolution (AAS) obtained is then extracted with 1,2-dichloroethane usinga separating funnel. The organic phases are then combined and dried overanhydrous sodium sulphate. The dissolved unsaponifiable fraction isfinally recovered after evaporating off the solvent and drying undervacuum. This step is carried out in a rotary evaporator, at 70° C.,under a vacuum of 1 mmHg for 2 hours. 141 g of unsaponifiable fractionfrom avocado are thus recovered, and are then stored under nitrogenwhile awaiting analysis.

The physicochemical and chromatographic analysis of this fraction gavethe following results:

-   -   peroxide value: 23.2 meq O₂/kg    -   saponification number: 11.3 mg KOH/g    -   incineration residue: 0.2%    -   furan lipid content: 57.6%    -   fatty alcohol content: 13.7    -   heavy compounds: 14.3%

EXAMPLE 3 Process for the Vigorous Heat Treatment of the Distillate

50 kg of fresh avocados are cut into thin slices 2 to 5 mm thick,including the kernel, using a disc slicer. The drying device is atemperature-regulated oven with a stream of hot air. The sliced avocadosare spread to a thickness of 4 to 5 cm onto staged trays. The dryingtemperature is set at 70° C. and its duration is 48 hours. Once dried,the fruit is ground and then subjected to a cold pressing. Thisoperation is performed on a small laboratory Komet press. The extractedoil is then filtered through a Büchner funnel, and then stored undernitrogen protected from light and moisture.

The oil obtained is then distilled in a Leybold KDL 4 wiped-filmmolecular distillation device, at a temperature of 230° C. and under avacuum of 10⁻³ mmHg. The yield of distillate for this operation is 9.9%.

This distillate is then heated at 85° C. for 48 hours, under acontinuous stream of nitrogen, in a glass reactor equipped with amechanical stirrer.

The oil obtained is saponified for 4 hours at reflux, in the presence of175 g of 50% potassium hydroxide and 875 g of ethanol, in a glassreactor equipped with a mechanical stirrer and on which is mounted acondenser. At the end of the reaction, the mixture is cooled to 30° C.and then diluted by adding demineralized water. The aqueous-alcoholicsolution (AAS) obtained is then extracted with 1,2-dichloroethane usinga separating funnel.

The organic phases are then combined and dried over anhydrous sodiumsulphate. The dissolved unsaponifiable fraction is finally recoveredafter evaporating off the solvent and drying under vacuum. This step iscarried out in a rotary evaporator, at 70° C., under a vacuum of 1 mmHgfor 2 hours. 163 g of unsaponifiable fraction from avocado are thusrecovered, and are then stored under nitrogen while awaiting analysis.The physicochemical and chromatographic analysis of this fraction gavethe following results:

-   -   peroxide value: 26.3 meq O₂/kg    -   saponification number: 10.7 mg KOH/g    -   incineration residue: 0.3%    -   furan lipid content: 62.2%    -   fatty alcohol content: 14.1    -   heavy compounds: 13.2%

Intermediate Conclusions

TABLE 1 Comparison of the various processes for obtaining theunsaponifiable fraction from avocado/Influence of the nature of the heattreatment Gain in Furan Heavy Peroxide yield lipids compounds valueExample Variant (1) (%) (1) (%) (2) (%) (meq O₂/kg) 1 Vigorous — 49.222.3 87.2 heating of the fruit 2 Vigorous +12% 57.6 14.3 23.2 heating ofthe oil 3 Vigorous +29% 62.2 13.2 26.3 heating of the distillate(1) Gain relative to Example 1 chosen as the reference process(2) Furan lipid content of the unsaponifiable fraction obtained

-   -   The standard process of vigorous heating of the fruit        (Example 1) gives a highly oxidized product (Ip=87.2 meq O₂/kg)        and has an appreciable content of heavy compounds (22.3%), these        compounds being derived from chemical condensation processes,        activated by the temperature and the long duration of the        process.    -   The process of vigorous heating of the oil, carried out under        inert atmosphere, allows an appreciable gain in yield (+12%        relative to the reference process of heating of the fruit). It        also leads to a product that is less oxidized (peroxide        value<30), with a lower content of heavy compounds (about 14% as        opposed to 22% previously) and, conversely, is richer in furan        lipids (57% as opposed to 49%).    -   The process of heating of the distillate itself offers a better        yield (+29%) and a high content of furan lipids in the final        unsaponifiable material (62%). Consequently, the overall yield        of furan lipids is thus greatly increased.

EXAMPLE 4 Process of Vigorous Heat Treatment of the Distillate in thePresence of a Catalyst

50 kg of fresh avocados are cut into thin slices 2 to 5 mm thick,including the kernel, using a disc slicer. The drying device is atemperature-regulated oven with a stream of hot air. The sliced avocadosare spread to a thickness of 4 to 5 cm onto staged trays. The dryingtemperature is set at 70° C. and its duration is 48 hours. Once dried,the fruit is ground and then subjected to a cold pressing. Thisoperation is performed on a small laboratory Komet press. The extractedoil is then filtered through a Büchner funnel, and then stored undernitrogen protected from light and moisture.

The oil obtained is then distilled in a Leybold KDL 4 wiped-filmmolecular distillation device, at a temperature of 230° C. and under avacuum of 10⁻³ mmHg. The yield of distillate for this operation is 9.9%.

This distillate is then heated at 85° C. for 2 hours in the presence of5% acidic alumina (catalyst), under a continuous stream of nitrogen, andin a glass reactor equipped with a mechanical stirrer.

The heat-treated distillate is filtered and saponified for 4 hours atreflux, in the presence of 175 g of 50% potassium hydroxide and 875 g ofethanol, in a glass reactor equipped with a mechanical stirrer and onwhich is mounted a condenser. At the end of the reaction, the mixture iscooled to 30° C. and then diluted by adding demineralized water. Theaqueous-alcoholic solution (AAS) obtained is then extracted with1,2-dichloroethane using a separating funnel.

The organic phases are then combined and dried over anhydrous sodiumsulphate. The dissolved unsaponifiable fraction is finally recoveredafter evaporating off the solvent and drying under vacuum. This step iscarried out in a rotary evaporator, at 70° C., under a vacuum of 1 mmHgfor 2 hours. 126 g of unsaponifiable fraction from avocado are thusrecovered, and are then stored under nitrogen while awaiting analysis.

The physicochemical and chromatographic analysis of this fraction gavethe following results:

-   -   peroxide value: 23.3 meq O₂/kg    -   saponification number: 11.3 mg KOH/g    -   incineration residue: 0.2%    -   furan lipid content: 71.5%    -   fatty alcohol content: 13.9    -   heavy compounds: 5.2%

EXAMPLE 5 Process for the Vigorous Heat Treatment of the Distillate inthe Absence of Catalyst

50 kg of fresh avocados are cut into thin slices 2 to 5 mm thick,including the kernel, using a disc slicer. The drying device is atemperature-regulated oven with a stream of hot air. The sliced avocadosare spread to a thickness of 4 to 5 cm onto staged trays. The dryingtemperature is set at 70° C. and its duration is 48 hours. Once dried,the fruits are ground and then subjected to a cold pressing. Thisoperation is performed on a small laboratory Komet press. The extractedoil is then filtered through a Büchner funnel, and then stored undernitrogen protected from light and moisture.

The oil obtained is then distilled in a Leybold KDL 4 wiped-filmmolecular distillation device, at a temperature of 230° C. and under avacuum of 10⁻³ mmHg. The yield of distillate for this operation is 9.9%.

This distillate is then heated at 85° C. for 2 hours, under a continuousstream of nitrogen, and in a glass reactor equipped with a mechanicalstirrer.

The heat-treated distillate is saponified for 4 hours at reflux, in thepresence of 175 g of 50% potassium hydroxide and 875 g of ethanol, in aglass reactor equipped with a mechanical stirrer and on which is mounteda condenser. At the end of the reaction, the mixture is cooled to 30° C.and then diluted by adding demineralized water. The aqueous-alcoholicsolution (AAS) obtained is then extracted with 1,2-dichloroethane usinga separating funnel.

The organic phases are then combined and dried over anhydrous sodiumsulphate. The dissolved unsaponifiable fraction is finally recoveredafter evaporating off the solvent and drying under vacuum. This step iscarried out in a rotary evaporator, at 70° C., under a vacuum of 1 mmHgfor 2 hours. 17 g of unsaponifiable fraction from avocado are thusrecovered, and are then stored under nitrogen while awaiting analysis.

The physicochemical and chromatographic analysis of this fraction gavethe following results:

-   -   peroxide value: 21.2 meq O₂/kg    -   saponification number: 10.1 mg KOH/g    -   incineration residue: 0.1%    -   furan lipid content: 70.1%    -   fatty alcohol content: 14.2%    -   heavy compounds: 3.2%

CONCLUSION

The addition of an alumina catalyst drastically increases the rate ofconversion since, after 2 hours of heat treatment, 126 g ofunsaponifiable material are obtained, as opposed to only 17 g in theabsence of alumina.

COUNTER EXAMPLE Process Without Vigorous Heat Treatment of the Fruit orits Optionally Concentrated Oil

50 kg of fresh avocados are cut into thin slices 2 to 5 mm thick,including the kernel, using a disc slicer. The drying device is aheat-regulated oven with a stream of hot air. The sliced avocados arespread to a thickness of 4 to 5 cm onto staged trays. The dryingtemperature is set at 65° C., and its duration is 72 hours. Once dried,the fruits are ground and then subjected to a cold pressing. Thisoperation is performed on a small laboratory Komet press. The extractedoil is then filtered through a Büchner funnel and then stored undernitrogen protected from light and moisture.

The oil obtained is then distilled in a Leybold KDL 4 wiped-filmmolecular distillation device, at a temperature of 230° C. and under avacuum of 10⁻³ mmHg. The yield of distillate for this operation is 9.1%.

The distillate obtained is saponified for 4 hours at reflux, in thepresence of 175 g of 50% potassium hydroxide and 875 g of ethanol, in aglass reactor equipped with a mechanical stirrer and on which is mounteda condenser. At the end of the reaction, the mixture is cooled to 30° C.and then diluted by adding demineralized water. The aqueous-alcoholicsolution (AAS) obtained is then extracted with 1,2-dichloroethane usinga separating funnel.

The organic phases are then combined and dried over anhydrous sodiumsulphate. The dissolved unsaponifiable fraction is finally recoveredafter evaporating off the solvent under vacuum at low temperature. Thisstep is carried out in a rotary evaporator, at 70° C., under a vacuum of1 mmHg, for 2 hours. 105 g of unsaponifiable fraction from avocado arethus recovered, and are then stored under nitrogen while awaitinganalysis.

The physicochemical and chromatographic analysis of this fraction gavethe following results:

-   -   peroxide value: 5.1 meq O₂/kg    -   saponification number: 11.3 mg KOH/g    -   incineration residue: 0.4%    -   furan lipid content: 5.2%    -   fatty alcohol content: 13.7    -   heavy compounds: 31.2%

CONCLUSION

In the absence of a step of vigorous heating of the fruit or of the oilwhich would result from unheated fruit, the furan lipid content of theunsaponifiable fraction from avocado obtained is extremely low(substantially less than 10%).

1-14. (canceled)
 15. A process for obtaining a furan lipid-richunsaponifiable material from avocado, comprising: (I) controllingdehydration of fresh avocados or of avocados that have undergone apreliminary transformation, wherein the dehydration is performed at atemperature of between −50° C. and 75° C., (II) extracting oil fromdehydrated fruit, (III) alternatively, a. heat treating the extractedoil at a temperature from 80 to 150° C., and then concentrating theunsaponifiable fraction of the oil, or b. concentrating theunsaponifiable fraction of the oil, followed by heat treating at atemperature from 80 to 150° C., followed by (IV) saponificating andextracting of the unsaponifiable material.
 16. The process for obtaininga furan lipid-rich unsaponifiable material from avocado according toclaim 15, wherein the step of heat treating in (III)(a) or (III)(b) iscarried out in the presence of a catalyst.
 17. The process for obtaininga furan lipid-rich unsaponifiable material from avocado according toclaim 16, wherein the catalyst is an acid catalyst of homogenous mineralor organic catalyst, chosen from the group of hydrochloric acid,sulphuric acid, acetic acid and para-toluenesulphonic acid, or aheterogeneous solid catalyst chosen from the group consisting of silica,alumina, silica-aluminas, zirconias, zeolites and acidic resins.
 18. Theprocess for obtaining a furan lipid-rich unsaponifiable material fromavocado according to claim 17, wherein the catalyst is of acidic aluminatype, with a specific surface area at least equal to 200 m²/g.
 19. Theprocess for obtaining a furan lipid-rich unsaponifiable material fromavocado according to claim 15, wherein the dehydration in step (I) isselected from the group consisting of drying under a stream of hot airat a temperature of between 70 and 75° C. or under a controlledatmosphere, drying at atmospheric pressure or under vacuum, microwavedrying, spray-drying, freeze-drying and osmotic dehydration in solutionor in solid phase.
 20. The process for obtaining a furan lipid-richunsaponifiable material from avocado according to claim 19, wherein thedehydration in step (I) consists in drying in ventilated dryers, in athin layer and under a stream of hot air, at a temperature of between 70and 75° C. for 8 to 36 hours.
 21. The process for obtaining a furanlipid-rich unsaponifiable material from avocado according to claim 15,wherein the step of extracting in (II) is carried out by a simple coldpressing or by the means of a solvent at low temperature.
 22. Theprocess for obtaining a furan lipid-rich unsaponifiable material fromavocado according to claim 15, wherein the step of concentrating in(III)(a) or (III)(b) is a cold crystallization or a moleculardistillation.
 23. The process for obtaining an unsaponifiable materialfrom avocado according to claim 22, wherein the step of concentrating isa molecular distillation which is performed at a temperature of between180 and 260° C. while maintaining a pressure of between 10⁻³ and 10⁻²mmHg.
 24. The process for obtaining a furan lipid-rich unsaponifiablematerial from avocado according to claim 15, wherein the step ofconcentrating in III(a) or III(b) is the molecular distillation and themolecular distillation is carried out in a device selected from thegroup consisting of molecular distillation devices of centrifugal typeand molecular devices of wiped-film type.
 25. The process for obtaininga furan lipid-rich unsaponifiable material from avocado according toclaim 15, wherein the saponification step of (IV) is carried out in thepresence of potassium hydroxide or sodium hydroxide in an alcoholicmedium, followed by one or more extractions.
 26. The process forobtaining a furan lipid-rich unsaponifiable material from avocadoaccording to claim 25, wherein the extraction takes place byliquid-liquid extraction with an organic solvent chosen from the groupconsisting of alkanes, haloalkanes, aromatic solvents and ethers. 27.The process for obtaining a furan lipid-rich unsaponifiable materialfrom avocado according to claim 25, wherein the organic solvent for theextraction is 1,2-dichloroethane.
 28. The process for obtaining a furanlipid-rich unsaponifiable material from avocado according to claim 15,further comprising a deodorization step.